Adjustable split seat

ABSTRACT

An adjustable seat that can be selectively adjusted to provide pressure relief for the back of the thighs and buttocks. The seat has two adjustable seat sections placed under the user&#39;s thighs. In one embodiment, the seat includes the main support body comprising a flat, horizontally aligned lower surface, a perpendicularly aligned, wide rear surface, a vertically aligned narrow front edge, a diagonally aligned upper support surface, and two equal vertically aligned side members. Disposed over the diagonally aligned support surface are two parallel, elastic wedge-shaped seat sections or two inflatable wedge-shaped seat sections. Each elastic or inflatable wedge-shaped seat section is complementary in shape and may create a flat seating surface on the seat accessory when the two wedge-shaped seat sections are longitudinally aligned over the diagonally aligned support surface. Each wedge-shaped seat section covers approximately one-half the diagonally aligned support surface. When one wedge-shaped seat section is removed from the main support body to accommodate the hip replacement patient&#39;s affected hip, which should not exceed 70° in flexion, the obtuse angle of the main support body supports the hip&#39;s approximate 70° angle of flexion. An optional attachment means is used to selectively connect each elastic wedge-shaped seat section to the main support body. With inflatable wedge seat sections, an air pump and control switch are also provided.

[0001] This is a utility patent application based on a provisional patent application (Ser. No. 60/203,742) filed on May 12, 2000.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to adjustable seats, and more particularly, to seats and seat accessories with adjustable thigh or seat supports intended to relieve pressure on the back of the thigh and buttock and allow individuals with hip flexion restrictions to sit.

[0004] 2. Description of the Related Art:

[0005] It is well known that prolonged sitting in a car, on a plane or in a chair results in leg discomfort, restlessness, and fatigue. Intermittent pressure relief for the back of the thighs and buttocks is required to prevent fatigue, skin breakdown, and blood clot formation. Special mechanical and weight limitations often prevent adequate leg movement to relieve such pressure on the thighs.

[0006] It is also well known that individuals who have undergone hip replacement surgery must limit their hip flexion for several weeks. Conventional chairs do not have the means to accommodate these needs while allowing the individual to sit in a normal fashion. In addition, there are no conventional chairs or seats which can accommodate hip flexion restrictions and provide intermittent pressure relief.

[0007] A limited moveable support seat for airplane pilots has been described by Shepherd et al. in U.S. Pat. No. 3,883,173. However, this type of seat was designed to allow for emergent downward movement of the anterior portion of the seat, which supports the front of the thigh near the knee. This type of seat does not address the need for relieving pressure on the entire thigh and buttock area to prevent excessive hip flexion as required after hip surgery.

SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to provide a seat that can be adjusted in such a way to relieve pressure on the back of the thigh and buttock of either leg.

[0009] It is another object of the present invention to allow individuals who have undergone hip surgery to sit with a reduced hip flexion for one leg.

[0010] It is another object of the present invention to provide a seat that can be used for either leg following hip replacement surgery.

[0011] It is another object of the present invention to provide a seat that can accommodate a reduced hip flexion angle, and provide additional intermittent pressure relief if necessary.

[0012] These and other objects are met by an adjustable split seat that includes two parallel seat sections that enable the user to independently and selectively adjust the angle of his or her upper legs with respect to his or her back. The seat is also designed to allow the user to straighten his or her legs while sitting for greater comfort.

[0013] In the first embodiment, the seat includes a main support body that has a flat, horizontally aligned lower surface, a wide vertically aligned rear surface, a narrow front edge, and a diagonally aligned, upper support surface. During use, the lower surface is positioned so that the rear surface is aligned adjacent to the back of the chair or seat and the upper support surface faces upward.

[0014] Disposed over the upper support surface are two elastic wedge-shaped seat sections. Each elastic wedge-shaped seat section is complementary in shape to create a flat seating surface parallel to the main support body's lower surface when the two elastic wedge-shaped seat sections are placed side-by-side and longitudinally aligned over the main support body's upper support surface. Each elastic wedge-shaped seat section covers approximately one-half the upper support surface. An optional attachment means is used to selectively connect each elastic wedge-shaped seat section to the upper support surface.

[0015] In the second embodiment, the two elastic wedge-shaped seat sections are replaced with two independent inflatable wedge-shaped seat sections connected to an air pump that selectively inflates and deflates the wedge-shaped seat sections.

[0016] In a third embodiment, the two seat sections are flat, rectangular or square-shaped structures pivotally mounted to the seat's rear transverse axis. Each seat section may independently pivot approximately 40° around the transverse axis. Each seat section is designed to be independently adjustable and includes an interior frame that pivots around, and extends forward from, a transverse axle located under the back section of the seat. A locking mechanism is provided between each interior frame and the transverse axle that enables the interior frame to be selectively rotated and locked in position around the transverse axle. A side handle is attached to the lateral ends of the transverse axle that is used by the user to selectively adjust the angle of the adjacent seat section.

[0017] During use, the user removes or deflates the elastic wedge-shaped seat section, or pivotally adjusts the angle of the seat section corresponding to the leg on the side of the body in which the hip replacement was performed. This allows the user to sit with reduced hip flexion on one side. Since the angle of hip flexion for a patient who has undergone hip replacement surgery should not exceed is 70°, the angle of the main support body or the amount of downward rotation of the pivoting seat section is limited to approximately 20° from the horizontal axis. When the split seat is used by an individual without hip surgery, the seat section may be removed, deflated, or adjusted so that the user adjusts the amount of pressure exerted on the back of either or both legs for comfort.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a perspective view of the first embodiment of the adjustable split seat with two independently removable seat sections.

[0019]FIG. 2 is a side elevational view of an individual seated in a chair with the assembled split seat.

[0020]FIG. 3 is a side elevational view of an individual seated in a chair with one seat section removed to allow the individual's hip flexion to be reduced.

[0021]FIG. 4 is a perspective view of the main support body used in the first embodiment.

[0022]FIG. 5 is a side elevational view of the first embodiment of the split seat.

[0023]FIG. 6 is a side elevational view taken along line 6-6 in FIG. 5.

[0024]FIG. 7 is a perspective view of the second embodiment of the adjustable split seat, which uses two inflated wedge-shaped seat sections.

[0025]FIG. 8 is a perspective view of the second embodiment of the invention showing one deflated wedge-shaped seat section.

[0026]FIG. 9 is a side elevational view showing the location of the air bladder in the inflatable wedge-shaped seat section.

[0027]FIG. 10 is a schematic diagram showing the two bladders connected to a switch and an air pump.

[0028]FIG. 11 is a perspective of a third embodiment of the adjustable split seat.

[0029]FIG. 12 is a side elevation view of the third embodiment of the adjustable split seat shown incorporated into a motor vehicle or plane seat.

[0030]FIG. 13 is a side elevation view of the user shown in FIG. 3 showing the adjustment of one seat section so that the user may straighten the leg and place the upper leg in alignment with the user's back.

[0031]FIG. 14 is a top plan view of the interior frame used in the third embodiment shown in a locked position.

[0032]FIG. 15 is a top plan view of the interior frame shown in an unlocked position.

[0033]FIG. 16 is a perspective view of the split seat design used in a standard office chair.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0034] Shown in the accompanying FIGS. 1-9, there is shown an adjustable split seat 10 designed to allow a hip replacement patient 80 to sit comfortably with a reduced hip flexion. Using the split seat 10 with one knee flexed and with the wedge-shaped seat section 42 removed, there is limited thigh contact with the seat 85 and the blood flow through the lower leg 82 is less restricted and the tissue pressure is reduced, as shown in FIG. 3. FIG. 1 shows the first embodiment of the split seat 10 before it is placed in position on a conventional chair 90. As shown more clearly in FIG. 4, the split seat 10 includes a main support body 20 made of a firm, yet flexible material, such as foam. In the preferred embodiment, for additional support and comfort, a rigid base layer 19 is registered and attached to the lower surface 11 of the main support body 20 so that the bottom surface 15 on the rigid base layer 19 makes contact with the seat 85. The main support body 20 includes a flat, horizontally aligned lower surface 11, a vertically aligned rear surface 12, a short front edge 13, a diagonally aligned, upper support surface 14, and two vertically aligned side members 16, 18 that are equal in size. The obtuse angle of the main support body 20 should not exceed 70°.

[0035] During use, the lower surface 15 of the base layer 19 is placed on the seat 85 of a chair 90 with the vertically aligned rear surface 12 being substantially aligned adjacent to the back 92 of the chair 90. As shown in FIGS. 1-3, disposed over the diagonally aligned upper support surface 14 of the main support body 20 are two parallel, elastic wedge-shaped seat sections 32, 42. As shown in FIG. 5, each elastic wedge-shaped seat section (seat section 42 shown) includes a flat, diagonally aligned, lower surface 41, a flat, horizontally aligned upper surface 34, a roughly square-shaped vertically aligned front member 35, and two equal-sized, vertically aligned side members 26 (not shown) and 36, respectively.

[0036] Each elastic wedge-shaped seat section 32, 42 is complementary in shape to create a flat seating surface when the two elastic wedge-shaped seat sections 32, 42 are longitudinally aligned over the upper support surface 14. Each elastic wedge-shaped seat section 32, 42 covers approximately one-half the upper support surface 14.

[0037] The elastic wedge-shaped seat sections 32, 42 may be attached to the upper support surface 14 by a temporary attachment means, such as hook and loop connectors 38, 40, as shown in FIGS. 4 - 6. The hook and loop connectors 38, 40 respectively, ensure that the elastic wedge-shaped seat sections 32, 42, respectively, do not move over the main support body 20. The hook and loop connectors 38, 40 are attached longitudinally aligned along the central axis of the diagonally aligned lower surface 31 (not shown), 41 of each elastic wedge-shaped seat sections 32, 42 and at the corresponding places on the upper support surface 14 of the main support body 20.

[0038] In the preferred embodiment, the seat sections 32, 42 measures approximately 18 inches in length, 18 inches in width, and 6 inches in height at the front. The upper support surface 14 is disposed at approximately 20 degrees above the horizontal axis so that the upper support layer 24, 34 on each elastic wedge-shaped seat section 32, 42 is parallel to the lower surface 11 of the main support body 20 and parallel to the lower surface 15 of the optional rigid base layer 19.

[0039]FIG. 2 shows a user 80 seated on a conventional chair 90, with the adjustable split seat 10 positioned on the seat 91 on the chair 90. The user's back 75 is in alignment with the back 92 of the seat accessory 10, and the user's knees are able to flex while each elastic wedge-shaped seat sections 32, 42 supports the length of each thigh individually.

[0040]FIG. 3 illustrates an example of a patient 80 using the split seat 10 to straighten his left lower leg 82 relative to his thigh 83. The elastic wedge-shaped seat section 42 corresponding to the straightened leg 82 has been removed thereby enabling the upper support surface 14 of the main support body 20 to fully support the left thigh 83 and reduce hip flexion on the left side from approximately 90° to approximately 70°. At the same time, the other elastic wedge-shaped seat section (not shown) remains in place to support the right thigh of the user 80 as the typical healthy person was meant to sit, i.e. parallel to the cushion 85 of a conventional chair 90. The angle of hip flexion that a hip replacement patient should not exceed is 70°. For this reason the obtuse angle of the main support body 20 is equal to or exceeds 70°, with the acute angle of the main support body equal to or less than 20°.

[0041] FIGS. 7-10 show a second embodiment of the seat 10′ where the elastic wedge-shaped seat sections 32, 42 are replaced with two inflatable wedge-shaped seat sections 27, 37 disposed over a main support body 20. Each inflatable wedge-shaped seat section 27, 37 includes an inner bladder 29, 39 connected to an air inlet conduit 70. The inner bladders 29, 39 are inflatable units made of plastic, vinyl, or other material conducive to containing air in a flexible container. Each air inlet conduit 70 is connected to a switch 75 used to activate a pump 78 and to control the direction of air to and from one of the air bladders 29, 39. In the preferred embodiment, the switch 75 is a four-way switch that enables the user to choose one of four positions to perform the following: 1) inflate right elastic wedge-shaped seat section 27, 2) deflate right elastic wedge-shaped seat section 27, 3) inflate left elastic wedge-shaped seat section 37, and 4) deflate left elastic wedge shaped seat section 37. In another embodiment (not shown) the switch 75 can be replaced by two switches each connected to one bladder 27, 37 and to the pump 78.

[0042] Shown in the accompanying FIGS. 11-16 is a third embodiment of the split seat 10″ also designed to allow the user 80 to comfortably sit with at least one leg substantially aligned with the back. Using the split seat 10″ with the knee flexed and with limited thigh contact with the seat, the blood flow through the lower leg 90 is less restricted. With the thigh resting on the lowered seat, the hip flexion is also reduced.

[0043] In the preferred embodiment, the seat 10″ includes a lower seat component 112 with back support 120. The seat component 112 includes two seat sections 114, 116 that pivot around the seat's rear transverse axis 130. Each seat section 114, 116 may pivot approximately 35° thereby relieving pressure on the back of the thigh and buttocks allowing improved blood flow in the leg. When the seat section 114 or 116 supporting the leg 90 is slanted downward and the back support 120 is rotated rearward, the user's lower leg 190 may be straightened in alignment with the user's back, as shown in FIG. 13.

[0044] As shown in FIGS. 14 and 15, each seat section 114, 116 includes an interior frame 140 and 142, respectively, that pivots around and extends forward from a transverse axle 132 longitudinally aligned with the seat's transverse axis 130. Each interior frame 140, 142 includes three longitudinally aligned extension arms 143 and one forward cross-member 145. Each frame 140, 142 also includes a rear cross-member 146 that rotates around the rear transverse axle 132. A locking mechanism 150 is provided between each interior frame 140, 142 and the transverse axle 132 that enables the interior frames 140, 142 to be selectively locked in position on the transverse axle 132. The locking mechanism 150 includes flanges 154, 155 attached to frames 140, 142 and two sliding sleeve members 157, 158. A side handle 160 is attached to the two lateral ends of the transverse axle 132 that is used by the user to selectively move the flanges 153, 154 into engagement with the sleeve members 157, 158 so that the angle of the adjacent seat section 114 or 116 may be adjusted.

[0045] The split seat 10″ may be used in a plane or motor vehicle seat 170 as shown in FIG. and 14 or in a standard office chair 180 as shown in FIG. 16.

[0046] In compliance with the statute, the invention has been described herein in language more or less specific as to structural features. It should be understood, however, the invention is not limited to the specific features shown, since the means and construction shown comprise only the preferred embodiments for putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the legitimate and valid scope of the amended claims, appropriately interpreted in accordance with the doctrine of equivalents. 

I claim:
 1. An adjustable split seat, comprising: a. a main support member with a diagonally aligned upper support surface, a lower surface, a narrow front edge, wide rear surface, and two side members, b. two fully extending wedge-shaped seat sections longitudinally aligned over the main support member capable of creating a flat seating surface parallel to said lower surface of said main support body; and, C. said wedge-shaped seat sections capable of being adjusted so that the amount of flexion on a leg disposed over said seat section is reduced.
 2. The seat as recited in claim 1 , wherein said wedge-shaped seat sections may be independently removed from said support member to reduce the amount of flexion on the leg to be disposed thereon when sitting.
 3. The seat as recited in claim 1 , wherein said wedge-shaped seat sections are adjustably inflatable to reduce the amount of flexion on a leg to be disposed thereon when sitting.
 4. The seat as recited in claim 1 , wherein said seat sections pivot about a rear transverse axis.
 5. The seat as recited in claim 4 , further including an adjustment handle enabling a user to independently adjust the position of each said seat section. 